1. Field of the Invention
The present invention relates to a projection display apparatus applied to a DMD (Digital Micromirror Device) projector, a liquid crystal projector, or the like, that projects an enlarged image onto a screen.
2. Description of the Background Art
Each of a DMD projector, a liquid crystal projector and the like has therein a projection display apparatus for projecting an enlarged image through a projection lens onto a screen. FIG. 19 is a perspective view partially showing the construction of a conventional projection display apparatus.
The projection display apparatus is constructed by fitting a lamp house 13 by insertion in which a lamp 1 as a light source is disposed into a lamp case 14. The face of each of the corners of side plates 15 of the lamp house 13 is formed as an inclined portion 15a and the remaining flat face is used as a contact portion 15b. In the case of fitting the lamp house 13 into the lamp case 14 by insertion, the contact portion 15b of the lamp case 13 is allowed to slide on an inner wall of the lamp case 14. In such a manner, the lamp house 13 is enclosed in the lamp case 14 and light of a predetermined quantity is distributed from the lamp 1.
In projection display apparatuses, in order to increase lamp efficiency, it is important to make the optical axis of the lamp 1 and that of an optical unit including the lamp case 14 coincide (align) with each other. The conventional projection display apparatus is, therefore, designed so that the optical axis of the lamp 1 and that of the optical unit coincide with each other when the lamp house 13 is fit to the lamp case 14 by insertion.
It is, however, extremely difficult to manufacture the parts constructing the lamp house 13 and the lamp case 14 strictly to the design dimensions. Generally, each of the component parts is finished within the range of a predetermined dimensional tolerance (range of the difference between the permissible maximum and minimum dimensions). As a result, in the conventional projection display apparatus, dimensional variations within the dimensional tolerance range of the parts constructing the lamp house 13 and the lamp case 14 are accumulated, and it is extremely difficult to make the optical axis of the lamp 1 and that of the optical unit coincide with each other with accuracy.
In order to supply electric power from a power source (not shown) to the lamp 1, a connector (not shown) for power supply is connected to each of the lamp house 13 and the lamp case 14. In the case of fitting the lamp house 13 into the lamp case 14 by insertion, the connectors provided for the lamp house 13 and the lamp case 14 have to be connected to each other. In the case of manufacturing the lamp house 13 and the lamp case 14, therefore, a positioning mechanism by which the connectors are properly connected to each other has to be provided. Due to an influence of the positioning mechanism for connecting the connectors, a problem such that the optical axis of the lamp 1 and that of the optical unit are further deviated from each other when the lamp house 13 is fitted into the lamp case 14 by insertion occurs.
A first aspect of the present invention is intended for a projection display apparatus for projecting an enlarged image onto a screen. According to the present invention, the apparatus comprises: an optical unit having a projection lens for projecting an enlarged image; a lamp case fixed to the optical unit; a lamp house in which a lamp holder to which a lamp for distributing light to the optical unit is fixed is movably disposed and which is detachably attached to the lamp case; lamp position regulating means for regulating a position of the lamp holder when the lamp house is attached to the lamp case, thereby positioning a center of the lamp onto an optical axis of the optical unit; and lamp posture regulating means for regulating a posture of the lamp holder when the lamp house is attached to the lamp case, thereby making an optical axis of the lamp and an optical axis of the optical unit parallel to each other.
Preferably, according to a second aspect of the present invention, the lamp holder has a circular arc wall face having a circular arc shape in cross section, a central axis of the circular arc wall face coinciding with the optical axis of the lamp; the lamp position regulating means is a V-shaped member having a V-shaped wall face which circumscribes the circular arc wall face at two points when the lamp house is attached to the lamp case; and the V-shaped member is fixed to the optical unit so that a point of intersection of two straight lines which pass through circumscribing points at which the V-shaped member circumscribes the circular arc wall face and are perpendicular to tangential lines at circumscribing points is positioned on an optical axis of the optical unit.
Preferably, according to a third aspect of the present invention, the optical unit has a reference face which is perpendicular to the optical axis of the optical unit, the lamp posture regulating means includes three or more projecting members each of which comes into contact with the reference face when the lamp house is attached to the lamp case, and the three or more projecting members are fixed to the lamp holder so that a flat face defined by the projecting members is perpendicular to the optical axis of the lamp.
Preferably, according to a fourth aspect of the present invention, the projection display apparatus further comprises an elastic member for generating a component force for pressing the circular arc wall face against the V-shaped member and a component force for pressing the three or more projecting members against the reference face.
Preferably, according to a fifth aspect of the present invention, a first connector for supplying electric power to the lamp is fixed to the lamp case, a second connector for supplying electric power to the lamp when being connected to the first connector is fixed to the lamp house, and the first and second connectors are connected to each other by making a guided member fixed to the lamp house slide along a guide member fixed to the lamp case.
Preferably, according to a sixth aspect of the present invention, the optical unit has therein a DMD chip and the projection lens enlarges and projects an image from the DMD chip.
Preferably, according to a seventh aspect of the present invention, the optical unit has therein a liquid crystal panel and the projection lens enlarges and projects an image from the liquid crystal panel.
As described above, according to the first aspect of the present invention, a projection display apparatus for projecting an enlarged image onto a screen, comprises: an optical unit having a projection lens for projecting an enlarged image, a lamp case fixed to the optical unit; a lamp house in which a lamp holder to which a lamp for distributing light to the optical unit is fixed is movably disposed and which is detachably attached to the lamp case; lamp position regulating means for regulating a position of the lamp holder when the lamp house is attached to the lamp case, thereby positioning a center of the lamp onto an optical axis of the optical unit; and lamp posture regulating means for regulating a posture of the lamp holder when the lamp house is attached to the lamp case, thereby making an optical axis of the lamp and an optical axis of the optical unit parallel to each other. Consequently, an influence by accumulation of dimensional variations of the component parts of the lamp house and the lamp case can be minimized. The optical axes of the lamp and the optical unit can be easily made coincide with each other irrespective of the dimensional variations of the component parts.
According to a second aspect of the present invention, the lamp holder has a circular arc wall face having a circular arc shape in cross section, a central axis of the circular arc wall face coinciding with the optical axis of the lamp; the lamp position regulating means is a V-shaped member having a V-shaped wall face which circumscribes the circular arc wall face at two points when the lamp house is attached to the lamp case; and the V-shaped member is fixed to the optical unit so that a point of intersection of two straight lines which pass through circumscribing points at which the V-shaped member circumscribes the circular arc wall face and are perpendicular to tangential lines at circumscribing points is positioned on an optical axis of the optical unit. Thus, the center of the lamp can be certainly positioned onto the optical axis of the optical unit, and the optical axes of the lamp and the optical unit can be easily made coincide with each other.
According to a third aspect of the present invention, the optical unit has a reference face which is perpendicular to the optical axis of the optical unit, the lamp posture regulating means includes three or more projecting members each of which comes into contact with the reference face when the lamp house is attached to the lamp case, and the three or more projecting members are fixed to the lamp holder so that a flat face defined by the projecting members is perpendicular to the optical axis of the lamp. Consequently, the optical axes of the lamp and the optical unit can be certainly made parallel to each other, and the optical axes of the lamp and the optical unit can be easily made coincide with each other irrespective of dimensional variations of the component parts.
According to a fourth aspect of the present invention, the projection display apparatus further comprises an elastic member for generating a component force for pressing the circular arc wall face against the V-shaped member and a component force for pressing the three or more projecting members against the reference face. The V-shaped member can stably circumscribe the circular arc wall face and the three or more projecting members are stably in contact with the reference face. Consequently, the optical axes of the lamp and the optical unit can be made coincide with each other with higher accuracy.
According to a fifth aspect of the present invention, a first connector for supplying electric power to the lamp is fixed to the lamp case, a second connector for supplying electric power to the lamp when being connected to the first connector is fixed to the lamp house, and the first and second connectors are connected to each other by making a guided member to be guided fixed to the lamp house slide along a guide member fixed to the lamp case. Consequently, the positioning for connecting the connectors and the adjustment of the optical axes of the lamp and the optical unit can be performed independent of each other. Thus, the optical axes of the lamp and the optical unit can be easily made coincide with each other without being influenced by the positioning mechanism for connecting the connectors.
It is therefore an object of the present invention to provide a projection display apparatus in which the optical axis of a lamp and that of an optical unit can be easily made coincide with each other irrespective of dimensional variations in the component parts.
Another object of the invention is to provide a projection display apparatus in which the optical axis of a lamp and that of an optical unit can be easily made coincide with each other without being influenced by a positioning mechanism for connecting connectors.